Manufacture of tubes by the push bench process



Nov. 27, 1934.

F. A. TROXEL MANUFACTURE OF TUBES BY THE PUSH BENCH PROCESS Filed July 2, 1932 INVENTOR MAL WT Patented Nov. 27, 1934 MANUFACTURE OF TUBES BY THE PUSH BENCH PROCESS Frank A. Tr oxel Aliquippa, Pa., assignor to Jones & Laughlin Steel Corporation, Pittsburgh, Pal, a corporation of Pennsylvania Application July 2, 1932, Serial No. 620,716

29 Claims.

This invention relates to the manufacture of tubes by the push bench process, and more particularly to methods and apparatus for'preparing a bottle for reduction and elongation by the push bench dies. It relates still more particularly to the manufacture of tubes by the push bench process in which the bottle 'is reshaped before it is pushed through the reducing dies.

In the push bench process of tube manufacture a heated billet is pierced or extruded,- or both, in a press to form what is known in the art as a bottle open at one end and closed at the other, and such bottle is placed over-the end of a mandrel and pushed through a series of aligned dies to thin and elongate the same. The dies successively reduce the bottle into a blank which u-ltimately becomes a finished tube.

- It is desirable that the push bench operate at high speed so crease the economy of the operation. The speed of passage of the bottle through a reducing die is governed by the amount of reduction which the die accomplishes, and this, in turn, is directly affected by .the shape of the bottle or blank as it enters such die. It is desirable that the bottle entering the push bench have a fairly uniformly tapered forward extremity or'nose, which is the closed end of the bottle formed in the press. However, due to considerations arising in the pressing operationit is difficult or impossible ,to produce in the press a bottle whose closed end or nose is precisely the desired shape for the push bench.

The bottle, as above mentioned, may be formed in the press either by a piercing or an extruding operation, or it may be formed by a combination piercing and extruding operation. For certain reasons, forming no part of the present invention, it is desirable to at least partially extrude the metal of the heated billet in the formation of the bottle, and the bottle may, for example, be formed by extruding the metal through a tapered or flared die which at the end of the bottle forming operation cooperates with a surface which extends generally inwardly toward the axis of the bottle at the closed end thereof, resulting in the formation of an outwardly pro- 'jecting fin at the exterior of the closed end of the bottle. A bottle having such a fin-is disclosed in British Patent No. 382,219. Such fin is undesirable so far as the push bench operation is concerned, but nevertheless the use of the flared die is desirable for the extrusion step in that it eases the flow of the metal.

Whether the bottle be made in accordance with to increase the output and inthe disclosure of the said Littler application or otherwise, it is desirable, in order that both the bottle forming operation and the push bench operation may be carried out with the greatest speed and efficiency, that the closed end of the bottle be reshaped before it is pushed through the reducing dies. For example, when a bottle having an outwardly projecting fin is. formed, the metal comprising such .fin may be forced back into the bottle'proper before the bottle is fed through the ring dies of the push bench. This intermediate operation permits of higher speeds at the commencement of pushing and insures against the presence of laps in the finished tube resulting from folding the fin back over the wall of the bottle.

Other objects and advantages of the invention will become apparent as the following description of a present preferred embodiment thereof proceeds.

In the accompanying drawing I have shown a present preferred embodiment of the invention, in which Figure 1 is a diagrammatic partial plan view of apparatus for the manufacture of tubes, with a portion in horizontal cross-section;

Figure 2 is'a cross-sectional view through a bottle having a fin thereon and showing diagrammatically an extrusion die for forming the same; and f Figure 3 is a cross-sectional view through a bottle after reshaping.

Referring more particularly to the drawin reference numeral 2 designates generally a push bench for the manufacture of tubes which comprises a ring bed 3 having therein reducing dies 4, a mandrel 5, a mandrel carrier 6, a. drive housing '7 and a motor 8. The specific mechanism of the push bench forms no part of the present invention, and the same may assume any well known form and consequently is shown in'the drawing only diagrammatically.

Reference-numeral 9 designates generally a press adapted to receive a heated billet and to form the same either by piercing or extrusion, or a combination of both, into a bottle open at one end and closed at the other end. The specific mechanism of the press may be varied as desired, although it is preferred to form the same in ac-' cordance with the disclosure of the aforementioned application of Carl W. Littler, and comprising a, tapered extrusion die illustrated diagrammatically at 10 in dotted lines in Figure 2. Inasmuch as the specific operating mechanism of the press forms no part of the present invention, and may assume any well known form, the

press is shown only diagrammatically. The press is adapted to form a bottle 11 as shown in crosssection in Figure 2 and having a closed end 12. Due to the fact that the die 10 has a flared surface 13 to ease the flow of the metal therethrough, the bottle is formed with an outstanding annular fin 14. It is undesirable to feed the bottle having the fin directly to the reducing dies of the push bench, as the fin slows up the pushing operation and also might result in the formation of laps in the finished tube due to the folding over of the fin against the wall of the bottle.

Pivotally mounted at 15 is a transfer arm 16 adapted to transfer the bottles 11 from the press 9. Such transfer arm has an enlarged outer extremity 17 in which is formed a lateral cavity 18 for the reception of a bottle. Such extremity of the transfer arm is adapted to be swung into position adjacent the press to receive a bottle and then to be swung into a position shown in dotted lines in Figure 1 to deliver the bottle to a table 19. The bottle transferred from the press is removed from the transfer arm at the table 19 and is then moved laterally to a position 20 where it is in alignment with a reshaping mandrel 21 and a reshaping die 22.

The reshaping mandrel 21 is carried by a piston 23 operable in a cylinder 24 and is adapted to be advanced axially of the bottle when the latter is at the position 20. A seat 25 is provided for positioning the bottle substantially in alignment with a guide 26 through which the mandrel 21 passes to enter the opening in the bottle. After the bottle is positioned in alignment with the mandrel 21, such mandrel is preferably advanced until its nose seats firmly against the interior of the nose of the bottle, and is then further advanced to carry the bottle forward until its nose engages the face of the reshaping die 22.

The reshaping die 22 has a tapered generally conical reshaping die face 27 through which is an axial opening 28. There is provided a cylinder 29 in which operates a piston 30 the forward extremity of which extends within the opening 28 and acts as a stripper to insure removal of the bottle from the reshaping die. The reshaping mandrel carrying the bottle is advanced until the nose of the bottle is pressed against the reshaping die, forcing the fin 14 into the metal of the bottle and reshaping the same from the shape shown in Figure 2 to that shown in Figure 3; The bottle as thus reshaped has a substantial- 1y smoothly tapered nose 32 ideal for passage through the reducing dies in the ring bed. Also, if desired, the interior of the nose of the bottle may be slightly reshaped, as shown at 33, to substantially closely conform to the nose of the push bench mandrel. This is accomplished by making the nose of the reshaping mandrel substantially the same shape as that of the push bench mandrel, both the interior and exterior of the closed end of the bottle being reshaped at the same time upon cooperation of the mandrel 21 and die 22.

After the reshaping operation, the mandrel 21 is retracted to the position shown in Figure 1, the guide 26 serving as a stripper to prevent the bottle from moving with the reshaping mandrel. The bottle will usually move with the reshaping mandrel andbe stripped therefrom by the guide 26, although if, as may sometimes occur, the bottlesticks within the reshaping die upon withdrawal of the mandrel the piston 30 is advanced to strip the bottle from the die. The reshaped bottle is then moved laterally to the position shown in dotted lines at 34, where the push bench mandrel 5 is advanced into the same for pushing it through the reducing dies in well known manner.

While I have shown and described a present preferred embodiment of the invention, it is to be distinctly understood that the same is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims.

I claim:

1. In the manufacture of tubes by the push bench process, the steps comprising forming a bottle closed at one end and open at the other, reshaping the closed end of the bottle, and subsequently thinning and elongating the bottle in a push bench.

2. In the manufacture of tubes by the push bench process, the steps comprising forming a bottle closed at one end and open at the other, bringing the closed end of the bottle while hot into contact with a die to reshape the same, and subsequently thinning and elongating the bottle in a push bench separate from said die.'

3. In the manufacture of tubes by the push bench process, the steps comprising forming a bottle closed at one end and open at the other, inserting a mandrel into the open end of the bottle, bringing the closed end of the bottle into contact with a die to reshape the same, and subsequently thinning and elongating the bottle in a push bench separate from said die.

4. In the manufacture of tubes by the push bench process, the steps comprising forming a bottle closed at one end and open at the other, inserting a reshaping mandrel into the open end of the bottle, then reshaping the closed end of the bottle independently of a push bench die, and

subsequently bringing a push bench mandrel into cooperative relationship with the bottle and thin- 6. In the manufacture of tubes by the push '1 bench process, the steps comprising forming a bottle closed at one end and open at the other, inserting a reshaping mandrel into the open end of the bottle, bringing the closed end of the bottle,

while the reshaping mandrel extends into thebench process, the steps comprising forming a bottle closed at one end and open at the other,

transferring the bottle to a position adjacent and generally parallel to a push bench, reshaping the closed end of the bottle at such position, moving the reshaped bottle laterally into the push bench,

and thinning and elongating the bottle in the push bench.

8. In the manufacture of tubes by the push bench process, the steps comprising forming a bottle closed at one end and open at the other and having a fin at its closed end, reshaping the closed end of the bottle by reducing such fln, and thinning and elongating the bottle in a push bench.

9. In the manufactureof tubes by the push bench process, the steps comprising forming by extrusion a bottle closed at one end and open at the other, reshaping the closed end of the bottle, and subsequently thinning and elongating the bottle-in a push bench.

10. In the manufacture of tubes by the push bench process, the steps comprising forming through a die flared toward the closed end thereof a bottle closed at one end and open at the other, reshaping the closed end of the bottle to reduce the exteriorly projecting portion thereof caused by the flared die, and thinning and elongating the bottle in a push bench.

11. In the manufacture of tubes by the push bench process, the steps comprising extruding through a die flared towardthe'closed end thereof a bottle closed at one end and open at the other, bringing the closed end of the bottle into contact with a reshaping die to reshape the same to reduce" the exteriorlypprojecting portion thereof caused by the flared die, and thinning and elongating the tube in a push bench.

-12. Apparatus for the manufacture of tubes, comprising a press for forming a bottle, reshaping means for reshaping the closed end only of said bottle, and a push bench for thinning and elongating the bottle.

13. Apparatus for the manufacture of tubes, comprising a press for forming a bottle, a substantially closed reshaping die for reshaping said bottle, transfer means for transferring the bottle from the press to the reshaping die, a push bench, and means for feeding the reshaped bottle to the push bench.

14. Apparatus for the manufacture of tubes, comprising a press for forming a bottle, means for reshaping the bottle comprising a mandrel and reshaping die so constructed and arranged as to prevent passage of the bottle therethrough, and a series of reducing dies for thinning and elongating the bottle.

15. Apparatus for the manufacture of tubes, comprising a press for forming a bottle, means for reshaping the bottle comprising a mandrel and ah axially movable reshaping die, and a series of reducing dies for thinning and elongating the bottle.

16. Apparatus for the manufacture of tubes, comprising a press for forming a bottle, a. push bench for thinning and elongating the bottle, reshaping means for reshaping the bottle adjacent but separate from the push bench, and means for moving the reshaped bottle laterally into the push bench.

17. Apparatus for the manufacture of tubes, comprising an extrusion press for forming a bottle, pressure reshaping means for reshaping such bottle, and a push bench separate from the reshaping means for thinning and elongating the bottle.

18. Apparatus for the manufacture of tubes, comprising an extrusion press having a die for forming a bottle, such die being flared toward the closed end of the bottle, reshaping means for reshaping such bottle to reduce the exteriorly projecting portion thereof caused by the flared and having its closed end of irregular conformation exteriorly thereof, reshaping the exterior of the closed end of the bottle, and thinning and elongating the bottle in a push bench.

21. Apparatus for the manufacture of tubes,

comprising apress for forming a bottle, reshaping means for reshaping the bottle, and a push bench separate from the reshaping means for thinning and elongating the bottle.

22. Apparatus for the manufacture of tubes, comprising a press for forming a bottle, a substantially closed reshaping die for reshaping the bottle, and a push bench for thinning and elongating the bottle.

23. Apparatus for making tubes, comprising means for forming an elongated hollow'blank from a relatively short metal body, a push bench, and means intermediate the blank forming means and the push bench for pressing the blank and reshaping the exterior of an end of the same.

24. A method of making tubes, comprising piercing a metal body, reducing a cross-sectional dimension thereof and elongating the same, whereby to form a blank, reshaping a portion of the exterior of the blank by direct pressing, and

thinning and elongating the reshaped blank to form a tube. v

25. A method of making tubes, comprising piercing and extruding a metal body to form a blank, reshaping a portion of the exterior of the blank by direct pressing, and thinning and elongating the reshaped blank to form a tube.

26. In the manufacture of tubes, the steps comprising piercing a metal body throughout a portion of its length and so as to leave a closed end, reducing a cross-sectional dimension of such body and elongating the same and forming therefrom a blank having an exterior projection at such closed end, reshaping the exterior of such end of the blank by pressing, and placing the reshaped blank on a mandrel and pushing the same through a series of dies to thin and elongate it and form a tube.

27. Apparatus for the manufacture of tubes comprising means for elongating a metal body and forming it into a hollow blank, pressing means cooperable with an end of such blank for reshaping the exterior of such end, and a push bench for forming the reshaped blank into a tube.

28. In the manufacture of tubes, the steps comprising forming a hollow blank closed at one end and having an exterior fin, removing such fin, and thinning and elongating the blank over a mandrel in a push bench to form a tube.

29. In the manufacture of tubes, the steps comprising forming a hollow blank closed at one end, reshaping a portion of said blank by direct pressing, and thinning and elongating the blank over a mandrel in a push bench to form a tube.

FRANK A. TROXEL. 

